Compilare: main.cpp: In function 'int main()': main.cpp:32:35: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::pair<int, int> >::size_type {aka long unsigned int}' [-Wformat=] printf ( "%d" , v.size () ) ; ^ main.cpp:44:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 1 ; i < v.size () ; ++ i ) ~~^~~~~~~~~~~ main.cpp:52:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v.size () ; ++ i ) ~~^~~~~~~~~~~ main.cpp:64:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while ( st - 1 >= 0 && dr + 1 < v.size () && v [ st - 1 ].first == v [ dr + 1 ].first && v [ st - 1 ].second + v [ dr + 1 ].second >= 3 ) ~~~~~~~^~~~~~~~~~~ main.cpp:70:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v.size () ; ++ i ) ~~^~~~~~~~~~~ main.cpp:75:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v.size () ; ++ i ) ~~^~~~~~~~~~~ main.cpp:11:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "arc.in" , "r" , stdin ) ; ^ main.cpp:12:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen ( "arc.out" , "w" , stdout ) ; ^ main.cpp:16:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d" , & c , & n ) ; ^ main.cpp:18:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , & x ) ; ^ main.cpp:23:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d" , & x ) ; ^